The exemplary embodiment relates to the field of image retrieval and selection. It finds particular application in the context of a navigation system and method for searching a database of images.
Digital images are acquired and stored in large numbers for later use in connection with a variety of applications, such as commercial design, editorial work, professional digital photography, and asset management. Retrieval of images by conventional searching techniques is often time consuming. For example, if a collection has been tagged appropriately, a user may enter a textual query, such as “flower,” and retrieve a large number of images responsive to the query, e.g., those which have been manually tagged as containing flowers. Other methods for retrieval are based on feature extraction techniques. For example, an automated system may propagate tags of manually labeled images to unlabeled images based on similarity of extracted features. Or, the user may input an image of a flower and similar images are retrieved automatically by comparing the features of the input image with those of the stored images.
Image searching generally entails a compromise between narrowly defining and delimiting the search space through the use of explicit criteria, and browsing a sufficiently large sample of the available images to ensure that the most suitable or aesthetically appealing ones are not missed. This leaves the user with a relatively large subset of images. Thus, browsing remains the primary method for section of images.
Current systems, such as Google Images™ and FLICKR™ image systems, perform image searches based on content and provide very basic options for aesthetic refinement. However, they do not provide tools for feature combination searches. At best, they allow users to select and chain together a sequence of refinement criteria. For example in Google Images, a user can search by content such as the query “sky” and then click on the “blue” box to get the blue sky images. This type of browsing makes moving back and forth between selected feature refinements and exploration of different combinations of features impractical.